U.S. patent application number 11/529874 was filed with the patent office on 2007-04-12 for actuator for adjusting a rotor blade pitch angle.
Invention is credited to Klaus-Peter Mollhagen.
Application Number | 20070081896 11/529874 |
Document ID | / |
Family ID | 36869917 |
Filed Date | 2007-04-12 |
United States Patent
Application |
20070081896 |
Kind Code |
A1 |
Mollhagen; Klaus-Peter |
April 12, 2007 |
Actuator for adjusting a rotor blade pitch angle
Abstract
Actuator for adjusting pitch angle of a rotor blade of a wind
turbine rotatably mounted on a rotor hub, comprising a first drive
element connectable with the rotor blade, a second drive element in
meshing engagement with said first drive element, a lubricating
device for lubricating the two drive elements and lubrication
controller. A rotor with a rotor hub, on which at least one rotor
blade is rotatably mounted, with actuator adjustable pitch angle. A
wind turbine comprising such rotor and such actuator. Selective
lubrication of zero teeth of the gear stage of the actuator
considers the rotary position of the drive elements of the gear
stage with respect to each other. The lubricating device includes a
lubricant passage to selectively supply portion of first drive
element and/or portion of second drive element meshing therewith
depending on engagement position of drive elements or rotary
position of rotor blade.
Inventors: |
Mollhagen; Klaus-Peter;
(Memmingen, DE) |
Correspondence
Address: |
PETERS VERNY , L.L.P.
425 SHERMAN AVENUE
SUITE 230
PALO ALTO
CA
94306
US
|
Family ID: |
36869917 |
Appl. No.: |
11/529874 |
Filed: |
September 29, 2006 |
Current U.S.
Class: |
416/98 |
Current CPC
Class: |
Y02E 10/72 20130101;
F03D 80/70 20160501; F05B 2260/98 20130101; F05B 2260/70
20130101 |
Class at
Publication: |
416/098 |
International
Class: |
B64C 27/54 20060101
B64C027/54 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 7, 2005 |
DE |
20 2005 015 774.0 |
Claims
1. An actuator for adjusting the pitch angle of a rotor blade (2)
of a wind turbine (3), which is rotatably mounted on a rotor hub
(1), comprising a first drive element (4) connectable with the
rotor blade (2), a second drive element (5) in meshing engagement
with said first drive element (4), as well as a lubricating device
(6) for lubricating the two drive elements (4, 5), characterized in
that the lubricating device (6) has a lubricant passage (7) for the
selective supply of lubricant to the portion (8) of the first drive
element (4) and/or the portion (9) of the second drive element (5),
which are in engagement with each other when the rotor blade (2) is
in its preferred working position, and a supply control means (10)
for controlling the supply of lubricant through said lubricant
passage (7) in dependence on the engagement position of the two
drive elements (4, 5).
2. The actuator as claimed in claim 1, wherein the supply control
means (10) includes an enabling switch, which activates the supply
of lubricant through the lubricant passage (7) when said two drive
elements (4, 5) are in engagement with each other with their
portions (8, 9), and which blocks the supply of lubricant through
the lubricant passage (7) when said two portions (8, 9) are out of
engagement.
3. The actuator as claimed in 1, wherein the supply control means
(10) includes a valve (12) in the lubricant passage (7), in
particular at the orifice region thereof, which can be actuated in
dependence on the engagement position of the two drive elements (4,
5) and/or in dependence on the pitch angle of the associated rotor
blade.
4. The actuator as claimed in claim 3, wherein the valve (12)
includes a valve opener (13) which is movable between an opening
position and a closing position and protrudes in the vicinity of
the orifice of the lubricant passage (7).
5. The actuator as claimed in claim 4, wherein the valve opener
(13) includes a valve tappet which extends in the lubricant passage
(7) and protrudes from the same and opens the valve (12) by being
depressed into the lubricant passage (7).
6. The actuator as claimed in 3, wherein the valve (12) constitutes
a check valve whose shut-off member (14) is actuated towards the
closing position of the valve by the lubricant pressure in the
lubricant passage (7).
7. The actuator as claimed in claim 1, wherein the lubricant
passage (7) opens into a tooth base region of the first and/or
second drive element (4, 5).
8. The actuator as claimed in claim 1, wherein the lubricant
passage (7) is passed through the second drive element (5) and/or
the supply control means (10, 12) is arranged in the second drive
element (5).
9. The actuator as claimed in claim 8, wherein the lubricant
passage (7) can be brought into a flow connection with a lubricant
port (15) disposed on the end face of the second drive element
(5).
10. The actuator as claimed in claim 8, wherein the lubricant
passage (7) can be brought into a flow connection with a lubricant
port (15) provided on a drive shaft (16) and/or a drive shaft
housing (17).
11. The actuator as claimed in claim 10, wherein the lubricant
passage (7) is passed through a drive shaft (16) and communicates
with a drive shaft housing interior, in which bearings are
accommodated for supporting the drive shaft (16).
12. The actuator as claimed in claim 1, wherein the lubricant
passage (7) is passed through a drive shaft bearing housing (17) or
through the rotor hub (1) and/or opens on the end face onto the
toothing of the two drive elements (4, 5).
13. The actuator as claimed in claim 12, wherein at least on one of
said portions (8, 9) of the two drive elements (4, 5) an actuating
cam (18) is provided for opening the valve (12).
14. The actuator as claimed in claim 1, wherein the lubricant
passage (7) is passed through the first drive element (4) and/or a
bearing portion (19) supporting the first drive element (4).
15. The actuator as claimed in claim 14, wherein the lubricant
passage (7) is passed through the first drive element (4) and the
bearing ring (19) such that the corresponding lubricant passage
portions (7a, 7b) are in flow connection with each other only in
one rotary position of the first drive element (4) relative to the
bearing portion (19).
16. The actuator as claimed in claim 1, wherein the first drive
element (4) is a stewing ring and the second drive element (5) is a
drive pinion extending inside the slewing ring.
17. The actuator as claimed in claim 1, wherein the first drive
element (4) forms a bearing ring of a rotary bearing (20), by means
of which the rotor blade (2) can be supported on the rotor hub (1),
where in particular the first drive element (4) forms the inner
ring of the rotary bearing (20) and has an internal toothing with
which meshes the second drive element (5).
18. The actuator as claimed in claim 16, wherein the second drive
element (5) is seated on a drive shaft which is connectable with an
actuator motor (21) and/or forms the motor shaft thereof.
19. The actuator as claimed in claim 17, wherein the second drive
element (5) is seated on a drive shaft which is connectable with an
actuator motor (21) and/or forms the motor shaft thereof.
20. A rotor for a wind turbine (3) comprising an actuator (22) as
claimed in claim 1.
21. The rotor as claimed in claim 20, wherein the rotor blade (2))
is seated on an internally toothed slewing ring (4) of a roller
bearing (20) supported on the rotor hub (1), and can be driven by a
drive pinion (5) arranged coaxially with the roller bearing (20),
which is seated on a drive shaft (16) supported on the rotor hub
(1) via a drive shaft bearing housing (17).
21. A wind turbine comprising a rotor (23) as claimed in claim 19.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an actuator for adjusting
the pitch angle of a rotor blade of a wind turbine, which is
rotatably mounted on a rotor hub, comprising a first drive element
connectable with the rotor blade, a second drive element in meshing
engagement with said first drive element, as well as a lubricating
device for lubricating the two drive elements. The invention
furthermore relates to a rotor with a rotor hub, on which at least
one rotor blade is rotatably mounted, whose pitch angle can be
adjusted by an actuator as mentioned above. Finally, the invention
relates to a wind turbine comprising such rotor and such
actuator.
[0003] 2. Description of the Prior Art
[0004] Wind turbines regularly employ rotors whose rotor blades are
rotatably mounted on the rotor hub, so that the pitch angle of the
rotor blades can be adjusted. By means of large roller bearings,
the rotor blades can be mounted at the rotor hub so as to be
rotatable about their longitudinal axis, so that an actuator
accommodated inside the rotor hub can change the pitch angle of the
rotor blades. For this purpose, so-called pitch drives are used, as
they are disclosed for instance in DE 200 17 994 U1. Preferably,
the drive movement of an actuator motor is transmitted to the rotor
blade via a gear stage. Advantageously, the rotor blade can be
flanged directly onto the inner ring of the large roller bearing,
which constitutes a stewing ring and has an internal toothing with
which a drive pinion is meshing, which is arranged inside the
slewing ring and is seated on a drive shaft.
[0005] Of course, the actuators in such rotors of wind turbines
must be lubricated. An example for a lubricating device in the
rotor of a wind turbine is shown for instance in DE 200 21 026 U1.
A lubrication problem arises for instance in that the pitch angle
of the rotor blades is not frequently changed, as there is an
optimum pitch angle for the rotor blades over a wide wind range, so
that the rotor blades actually are only twisted when the wind is
too strong or the turbine must be stopped for maintenance purposes.
This leads to the fact that the actuators remain in the same
position for most of the operating time, and in the gear stage of
the actuator always the same pair of teeth of the meshing drive
elements is in engagement with each other. The lubricant thereby
can be displaced, so that an increased wear occurs at this pair of
teeth. The pair of teeth of the stewing ring and of the drive
pinion, which is in engagement with each other in the optimum pitch
angle position of the rotor blades, often is also referred to as
pair of zero teeth or as zero tooth. These zero teeth of the drive
elements in the wind turbine rotors gradually suffer from chipping
at their tooth flanks and exhibit strong wear after some time. The
torques resulting from the attack of wind must always be tolerated
at the same point of attack, which is even aggravated by vibrations
and oscillations likewise suffered by the tooth engagement.
[0006] To avoid these problems it has already been proposed to
offset the meshing drive elements with respect to each other after
some time, so that in the working position of the rotor blade they
are meshing with other teeth. In the case of wind turbines,
however, this is not easily possible merely because of the enormous
dimensions of the turbine. A disassembly of the rotor blade is
extremely time-consuming. Even inside the rotor hub, the actuator
cannot easily be repositioned. Therefore, it has already been
considered to provide the meshing drive elements with an associated
lubricating wheel which meshes with one of the drive elements and
transfers lubricant onto the same. From time to time, the actuator
is operated, in order to thereby ensure lubrication. However, such
design of the lubricating device is very costly. In addition, the
pitch angle of the rotor blades must be changed at undesired
times.
SUMMARY OF THE INVENTION
[0007] Therefore, it is the object underlying the invention to
create an improved actuator, an improved rotor and an improved wind
turbine as mentioned above, which eliminate the disadvantages of
the prior art and develop the latter in an advantageous way.
Preferably, the lubricating device should be improved such that the
so-called zero-degree teeth in the gear stage of the actuator can
sufficiently be lubricated with simple means.
[0008] In accordance with the invention, this object is solved by
an actuator as claimed in claim 1, a rotor as claimed in claim 19
as well as a wind turbine as claimed in claim 21. Preferred aspects
of the invention are subject-matter of the dependent claims.
[0009] There is thus proposed a selective lubrication of the
zero-teeth of the gear stage of the actuator, which advantageously
considers the rotary position of the drive elements of the gear
stage with respect to each other. In accordance with the invention,
the lubricating device has a lubricant passage for the selective
supply of lubricant to the portion of the first drive element
and/or the portion of the second drive element meshing therewith,
which in the working position of the rotor blade are in engagement
with each other, and a supply control means for controlling the
supply of lubricant through said lubricant passage in dependence on
the engagement position of the two drive elements or the rotary
position of the rotor blade. The supply control means ensures that
the zero tooth of the first drive element and/or of the second
drive element is only lubricated when the two drive elements are in
the proper position with respect to each other. In particular, the
supply control means can provide that lubrication only is effected
when the two zero teeth of the two drive elements actually are in
engagement with each other, and lubrication is not effected when,
for instance under too strong wind, the rotor blades are turned out
of the wind.
[0010] For this purpose, the supply control means can have an
enabling switch which activates the lubricant supply when said two
drive elements are in engagement with those portions with which
they are meshing in the working position of the rotor blade, and
which blocks the lubricant supply when said two drive element
portions are out of engagement. The supply control means arms the
lubricant supply, so to speak, which does not mean that lubricant
must be supplied constantly when the rotor blades are in their
working position and the zero teeth are in engagement with each
other. A time pulse control, a time sequence control or the like
can of course be superimposed on said principal activation of the
lubricant supply, so that lubricant is supplied for instance in
predetermined intervals, but only when the zero teeth actually are
in engagement with each other.
[0011] For controlling the supply of lubricant, the aforementioned
lubricant passage can in particular include a valve, which can be
disposed in particular in the orifice region of the lubricant
passage. The valve advantageously is designed such that it can be
actuated in dependence on the engagement position of the two drive
elements to be lubricated, and is opened in particular when the
drive element portions to be lubricated are in engagement with each
other, and is closed when these two drive element portions are out
of engagement.
[0012] In accordance with a preferred embodiment of the invention,
the valve can include a mechanical valve opener, which is movable
between an opening position and a closing position and protrudes in
the vicinity of the orifice of the lubricant passage, so that it
will open the valve by being depressed. In particular, the valve
opener is disposed on the one drive element such that it is
actuated by the other drive element, when said other drive element
meshes with the corresponding portion of the first-mentioned drive
element.
[0013] Instead of such mechanical valve opener, which is actuated
by the engagement portion to be lubricated of one of the two drive
elements, an electronic or hydraulic valve control might also be
provided, for instance such that the rotary position of the rotor
blade and/or the engagement position of the drive elements is
detected by means of a sensor and in response thereto, the valve is
actuated by a correspondingly designed control means. The
aforementioned embodiment of the valve with a mechanical valve
opener is, however, much easier to provide and operates completely
without failure, as the valve necessarily is actuated when the
drive elements are meshing with each other with their zero teeth.
Preferably the valve opener is actuated by one of the zero teeth of
the drive elements.
[0014] In accordance with an advantageous embodiment of the
invention a shut-off valve, possible in the form of a check valve,
can be provided in the lubricant passage, which valve is closed by
the lubricant pressure existing in the lubricant passage. The valve
opener is provided at the shut-off member and extends out of the
orifice of the lubricant passage, so that the shut-off member will
open against the lubricant pressure by depressing the valve
opener.
[0015] In principle, the lubricant passage can be passed in various
ways to the portions or sectors of the drive elements to be
lubricated. When the gear stage to be lubricated is formed by a
drive pinion and a slewing ring connectable with the rotor, a
particularly advantageous embodiment of the invention consists in
that the lubricant passage is passed through the drive pinion and
opens at the zero tooth thereof, wherein the orifice can be
provided in the vicinity of a tooth base, but also in the vicinity
of a tooth tip. An orifice in the vicinity of the tooth base is
preferred, as in this case the tooth itself is not weakened by the
lubricant bore.
[0016] Preferably, the lubricant passage in the drive pinion
extends radially to the outside and opens in the vicinity of the
tooth base of that tooth which in the working position of the rotor
blade meshes with a tooth of the stewing ring. The lubricant
passage is supplied with lubricant from a lubricant port which
communicates with the lubricant passage via a central rotary joint
inside the drive pinion. Preferably, the lubricant port can be
provided on the end face of the drive pinion. Alternatively, the
lubricant passage can also be passed into the drive shaft on which
the drive pinion is seated. In this case, the lubricant port can
advantageously be seated on a drive shaft bearing housing, so that
lubrication is effected through a bearing portion of the drive
shaft. The lubricant is pressed into the bearing housing, so to
speak, where it can lubricate the drive shaft bearings, and enters
the drive shaft, in which the lubricant is selectively passed
through the aforementioned lubricant passage onto the zero tooth to
be lubricated.
[0017] Alternatively or in addition to a supply of lubricant
through the drive pinion, the supply of lubricant can also be
effected through the stewing ring. In this case, the lubricant
passage preferably extends radially through the slewing ring and
opens in the vicinity of the zero tooth of the toothing of the
stewing ring, which in the preferred working position of the rotor
blade is in engagement with the drive pinion. Here as well, the
orifice region of the lubricant passage can in principle be
arranged both in the vicinity of the tooth base and in the vicinity
of the tooth tip, but here as well an orifice in the vicinity of
the tooth base is preferred for the above reasons.
[0018] If, in accordance with an advantageous embodiment of the
invention, the slewing ring forms a bearing ring of a large roller
bearing, by means of which the rotor blade is mounted on the rotor
hub, the lubricant passage preferably is also passed through the
second bearing ring of the large roller bearing on which the
slewing ring is supported. Here, the lubricant supply can be passed
through the rolling member cage, so that the rolling members of the
large roller bearing are lubricated at the same time. A particular
embodiment can also consist in that the lubricant passage is passed
through the two bearing rings such that the two portions of the
passage only communicate with each other when they overlap each
other in a certain position of the bearing rings with respect to
each other. As a result, the valve described above can possibly be
omitted. When the lubricant passage is passed through the outer
bearing ring such that it only communicates with the portion of the
lubricant passage in the inner bearing ring when the rotor blade is
in the preferred working position, the supply of lubricant is
controlled automatically, so to speak.
[0019] Alternatively or in addition to such supply of lubricant
through the rotor blade bearing, the lubricant can also be supplied
to the meshing pair of drive elements laterally or via the end
face. For this purpose, the lubricant passage can extend for
instance through a wall of the rotor hub or in particular through
the drive shaft bearing housing and can have an orifice which is
located on the end face of the engagement portion of the two
meshing drive elements of the gear stage. If there is provided a
valve with a protruding valve opener in the lubricant passage, as
described above, an actuator can be provided at the zero tooth to
be lubricated of the one or other drive pinion, for instance in the
form of a protruding actuating cam, which depresses the valve
opener and thereby activates the supply of lubricant, when the zero
teeth of the two drive elements are in the engagement position.
[0020] The present invention relates to an actuator for adjusting
the pitch angle of a rotor blade of a wind turbine, which is
rotatably mounted on a rotor hub, comprising a first drive element
connectable with the rotor blade, a second drive element in meshing
engagement with said first drive element, as well as a lubricating
device for lubricating the two drive elements. The invention
furthermore relates to a rotor with a rotor hub, on which at least
one rotor blade is rotatably mounted, whose pitch angle can be
adjusted by an actuator as mentioned above. Finally, the invention
relates to a wind turbine comprising such rotor and such actuator.
There is proposed a selective lubrication of the zero teeth of the
gear stage of the actuator, which advantageously considers the
rotary position of the drive elements of the gear stage with
respect to each other. In accordance with the invention, the
lubricating device includes a lubricant passage for the selective
supply of lubricant to the portion of the first drive element
and/or the portion of the second drive element meshing therewith,
which are in engagement with each other in the working position of
the rotor blade, as well as a supply control means for controlling
the supply of lubricant through said lubricant passage in
dependence on the engagement position of the two drive elements or
the rotary position of the rotor blade. The supply control means
ensures that the zero tooth of the first drive element and/or of
the second drive element only is lubricated when the two drive
elements are in the proper position for this purpose. In
particular, the supply control means can provide that lubrication
only is effected when the two zero teeth of the two drive elements
actually are in engagement with each other and lubrication is not
effected when, for instance under too strong wind, the rotor blades
are turned out of the wind.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The invention will subsequently be described in detail with
reference to preferred embodiments and associated drawings, in
which:
[0022] FIG. 1 is a partial perspective view of a wind turbine,
which shows a partial section of the nacelle of the wind turbine,
which is mounted on a tower, and the rotor mounted thereto
including the rotor blades,
[0023] FIG. 2 is a section through the actuator arranged in the
rotor hub of the wind turbine of FIG. 1, which serves to adjust the
pitch angle of the rotor blades of the wind turbine of FIG. 1, in
which the zero teeth of the gear stage are lubricated by a supply
of lubricant through the drive pinion,
[0024] FIG. 3 is an enlarged representation of the lubricant
passage and the valve disposed therein, in the drive pinion of the
actuator of FIG. 2,
[0025] FIG. 4 is a section through the actuator for adjusting the
rotor blade pitch angle in accordance with a further embodiment of
the invention, in which a lubricant passage in the drive pinion is
supplied with lubricant via a lubricant passage in the drive shaft
and through a drive shaft bearing housing,
[0026] FIG. 5 is an enlarged sectional view of the drive shaft and
of the drive shaft bearing housing of FIG. 4, which shows the
supply of lubricant via the drive shaft,
[0027] FIG. 6 is a section of an actuator for adjusting the rotor
blade pitch angle in accordance with a further preferred embodiment
of the invention, in which the zero teeth of the gear stage to be
lubricated are lubricated via a lubricant passage in the drive
shaft bearing housing and the lubricant is supplied via the end
face onto the drive pinion and the slewing ring meshing
therewith,
[0028] FIG. 7 is an enlarged sectional view of the lubricant
passage and the valve disposed therein, in the drive shaft bearing
housing of FIG. 6,
[0029] FIG. 8 is a section of an actuator for adjusting the rotor
blade pitch angle in accordance with a further embodiment of the
invention, in which the zero teeth of the gear stage to be
lubricated are lubricated via a lubricant passage through the large
roller bearing carrying the rotor blade,
[0030] FIG. 9 is an enlarged sectional view of the lubricant
passage through the bearing rings of the roller bearing of FIG. 8,
and
[0031] FIG. 10 is a cross-section through the drive pinion with
incorporated lubricant passage, for instance as shown in FIG. 2,
which shows the orifice of the lubricant passage in the tooth
base.
DETAILED DESCRIPTION OF THE INVENTION
[0032] In a manner known per se, the wind turbine 3 schematically
shown in FIG. 1 comprises a nacelle 25 mounted on mast or tower 24
so as to be rotatable about an upright axis, on which nacelle the
rotor 23 is rotatably mounted about a horizontal axis, in order to
drive a generator. In a manner known per se, the rotor 23 comprises
a rotor hub 1, which is rotably mounted about said horizontal axis
and carries a plurality of rotor blades 2 (three in the illustrated
embodiment), which are mounted on the rotor hub 1 so as to radially
protrude therefrom. The rotor blades 2 can be twisted about their
longitudinal axis relative to the rotor hub 1, so that the pitch
angle of the rotor blades 2 can be varied. For this purpose, an
actuator 22 is provided for each of the rotor blades 2 inside the
rotor hub 1, as is shown in FIG. 2. The actuator 22 comprises an
actuator motor 21, which can constitute an electric motor and is
flanged to a wall of the rotor hub 1 (cf. FIG. 2). Via a drive
shaft 16, the actuator motor 21 drives a drive pinion 5 seated on
the end face of the drive shaft 16, the axes of rotation of the
drive shaft 16 and of the drive pinion 5 being arranged parallel to
the adjustable rotor blade axis.
[0033] The respective rotor blade 2 is attached to the rotor hub 1
via a large roller bearing 20. In the illustrated embodiment, the
outer bearing ring 19 of the roller bearing 20 is flanged to the
rotor hub 1 and fastened there by means of screws, as shown in FIG.
2. The inner, rotatable bearing ring 4 of the roller bearing 20
carries the rotor blade 2, which is flanged to the end face of the
bearing ring 4 and is likewise fixed thereto by means of
screws.
[0034] Said bearing ring 4 of the bearing 20 forms a stewing ring
with an internal toothing 26, which meshes with the aforementioned
drive pinion 5. When the drive pinion 5 is rotated by the actuator
motor 21, this is translated into a corresponding change of the
pitch angle of the rotor blade 2.
[0035] As is furthermore shown in FIG. 2, the drive shaft 16 of the
actuator 22 is supported on the rotor hub 1 via a drive shaft
bearing housing 17. As shown in FIG. 2, the drive shaft 16 is
suitably supported on the drive shaft bearing housing 17 via roller
bearings.
[0036] For lubricating the gear stage 27 formed by the drive pinion
5 and the stewing ring 4, a lubricating device 6 is provided, by
means of which lubricant can selectively be supplied onto the zero
teeth of the drive pinion 5 and of the stewing ring 4. These
so-called zero teeth 8 and 9 are teeth of the drive pinion 5 and of
the slewing ring 4, which are in engagement with each other when
the rotor blade 2 has been rotated into its optimum pitch angle
position for normal wind conditions.
[0037] In the embodiment shown in FIGS. 2 and 3, the lubricating
device 6 comprises a lubricant port 15 provided on the end face of
the drive pinion 5, which via a rotary joint 28, which coaxially
extends into the drive pinion 5, communicates with a lubricant
passage 7 which inside the drive pinion 5 extends radially to the
outside. The lubricant passage 7 opens in the vicinity of the tooth
base of the aforementioned zero tooth, as is shown in FIG. 10.
[0038] The supply of lubricant via the lubricant passage 7 is
controlled by a supply control means 10, which via an enabling
switch 11 activates the supply of lubricant whenever the zero teeth
of the drive pinion 5 and of the slewing ring 4 are in engagement
with each other or the rotor blade 2 assumes its optimum pitch
angle position. In concrete terms, a valve 12 is therefore provided
in the lubricant passage 7, which in the manner of a check valve
comprises a shut-off member 14, which is biased into its closing
position via a spring 29 (cf. FIG. 3), the valve body 14 closing
the valve when it is moved towards the orifice 30 of the lubricant
passage 7.
[0039] For opening the valve 12, a valve tappet is provided as
valve opener 13, which has a rod-shaped design and extends away
from the valve body 14 through the lubricant passage 7 up to the
orifice 30 thereof. As shown in FIG. 3, the valve tappet 13
slightly protrudes beyond the orifice 30 of the lubricant passage 7
in the vicinity of the tooth base of the drive pinion 5, so that
the valve 12 is opened by depressing the valve tappet 13, i.e. the
valve body 14 is urged from its closing position against the spring
force into the opening position. This will occur whenever the zero
tooth 8 of the slewing ring 4 meshes with the zero tooth 9 of the
drive pinion 5, i.e. engages in the corresponding tooth base region
of the drive pinion 5, as is shown in FIG. 10.
[0040] FIGS. 4 and 5 basically show a similar embodiment of the
lubricating device 6. Here as well, the supply of lubricant is
effected through the drive pinion 5 via a lubricant passage 7
radially formed here. In so far, corresponding reference numerals
were used for corresponding components. In contrast to the
embodiment described above, however, the supply of lubricant is not
effected from the end face of the drive pinion 5, but through the
drive shaft 16 from a lubricant port 15 provided at the drive shaft
bearing housing 17. As shown in FIGS. 4 and 5, the radial lubricant
passage 7 communicates with an axial lubricant bore 31 inside the
drive shaft 16, which at its end facing away from the drive pinion
5 is passed out of the drive shaft 16 through the radial bore 32,
where it opens into a drive shaft bearing housing interior 33. From
the outside of the drive shaft bearing housing 17 lubricant can be
pressed through the lubricant port 15 into said interior 33, so
that the bearings of the drive shaft 16 are lubricated at the same
time. In the interior 33, there are also arranged the bearings for
the drive shaft 16. The radial bore 32 communicates with this
interior and hence allows to supply lubricant into the lubricant
passage 7 and through the same to the zero teeth 8 and 9.
[0041] As shown in FIG. 5, the lubricant bore 31 can be
incorporated via the end face of the drive shaft 16 and can be
closed there by means of a plug.
[0042] Instead of the supply of lubricant through the drive pinion
5 as performed in the preceding Figures, the lubricant can also be
supplied from the outside via the end face onto the meshing zero
teeth 8 and 9 of the stewing ring 4 or the drive pinion 5. Such an
embodiment is shown in FIGS. 6 and 7. In the embodiment illustrated
here, the lubricant passage 7 extends in the drive shaft bearing
housing 17, in which the drive shaft 16 is accommodated. The
lubricant passage 7 extends substantially parallel to the axis of
rotation of the drive pinion 5 or the drive shaft 16 and opens onto
the engagement portion, in which the drive pinion 5 meshes with the
slewing ring 4. The orifice 30 is provided at the end face of the
drive shaft bearing housing 17 and is covered by the teeth of the
drive pinion 5.
[0043] In the embodiment as shown in FIG. 6, the lubricant passage
7 also includes the above-described valve arrangement with the
protruding valve tappet 13. In order to open the valve 12, however,
only when the above-described zero teeth 9 and 8 of the drive
pinion 5 and of the slewing ring 4 are meshing with each other, the
zero tooth 9 of the drive pinion 5 carries a protrusion on its end
face, which forms an actuating cam 18, by means of which the valve
tappet 13 is depressed and the valve 12 is opened. The other teeth
of the drive pinion 5 do not carry such actuating cam 18, so that
the valve 12 will only open when the zero teeth 8 and 9 are meshing
with each other and accordingly lie at the orifice of the lubricant
passage 7.
[0044] Another embodiment of the lubricating device 6 is shown in
FIGS. 8 and 9, and here as well the same reference numerals are
used as in the preceding embodiments for corresponding components.
The supply of lubricant is effected through the rotary bearing 20
and in particular through the slewing ring 4. The lubricant passage
7 radially extends through the two bearing rings 19 and 4 and opens
into the tooth base of the zero tooth 8 of the slewing ring 4, the
valve 12 here also being provided with the protruding valve opener
13 in a corresponding manner. It is interesting here that the
lubricant passage 7 is divided into the portions 7a and 7b, which
are formed on the one hand in the slewing ring 4 and on the other
hand in the stationary bearing ring 19. Therefore, the supply of
lubricant only is possible when the lubricant passage portions 7a
and 7b come to overlap each other and are aligned with each other,
which always is the case when the slewing ring 4 assumes the
position in which its zero tooth 8 is meshing with the zero tooth 9
of the drive pinion 5, i.e. the rotor blade 2 is in its optimum
pitch angle position. In this embodiment, the valve 12 could
possibly even be omitted, as in other positions the two passage
portions 7a and 7b are not in alignment, and in so far no supply of
lubricant can be effected. For this purpose, the transition from
the stewing ring 4 to the bearing ring 19 in the vicinity of the
passage portions 7a and 7b should be sealed correspondingly. On the
other hand, said transitional region advantageously is provided in
the vicinity of the rolling members 34 of the bearing 20, so that a
lubrication of the rolling members 34 can be achieved via the
bearing gap between the two bearing rings.
* * * * *